Wheel drive mechanism



1957 F. A. GLQMB ETAL WHEEL DRIVE MECHANISM 4 Sheets-Sheet 1 OriginalFiled April 27 1961 In 1/rz Zions. flan/1' 19; filer/25. Vzcfor was 1967F. A. GLOMB ETAL WHEEL DRIVE MECHANI SM 4 Sheets-Sheet 2 Original FiledApril 27. 1961 1967 F. A. GLOMB ETAL 3,344,879

WHEEL DR IVE MECHANI SM Original Filed April 27. 1961 4 Sheets-Sheet 5F. A. GLOMB ETAL 3,344,879

WHEEL DRIVE MECHANISM 4 Sheets-Sheet 4 Oct. 3, 1967 Original Filed April27. 1961 E o L '6) n mm W H Z a m aWw 1 m j r 4 M m M A o m w/ m p I Ef/ Z M P a a L j w E P m E n 3 a M B .I W a A w w T a u c, W m A z a P J5 a E s a m w o u w n O 7 H a 0 V E 1 m L a w m u R. v W m a a R W a m mu 5 M a F a M M a m w u a n w a P L 2 1 a L Mfla o m FLLLLL ewe w m w Ma a Z a a m M ow w w 52 1 8w w w w w w x m s a o R 6 a 0 8 a 0 w 4 a z 0m 6 0 0 a M m 2 z United States Patent 3,344,879 WHEEL DRIVE MECHANISMFrank A. Glomb, Glenwood, and Victor Wasynczuk, Chicago, IIL, assignorsto Barnes & Reinecke, Inc., a corporation of Delaware Continuation ofapplication Ser. No. 106,015, Apr. 27, 1961. This application Dec. 3,1965, Ser. No. 517,141 9 Claims. (Cl. 180--55) This applicationcomprises a continuation of our copending application Ser. No. 106,015,filed Apr. 27, 1961, now abandoned, assigned to the assignee hereof.

This invention relates to drive apparatus and in particular tomulti-torque drive apparatus for use such as in vehicle wheel drives.

One improved method of driving a wheeled vehicle is to provide a drivemeans, such as a hydraulic motor, at each wheel to be driven by means ofhydraulic fiuid delivered thereto from a suitable pump carried by thevehicle. The present invention is concerned with such a wheel driveapparatus wherein transmission means are provided at each wheel forproviding controlled variable speed and torque drive of the wheel.

Thus, a principal feature of the present invention is the provision of anew and improved wheel drive apparatus.

Another feature of the invention is the provision of such wheel driveapparatus including an improved transmission mechanism for providing acontrolled variable speed and torque drive.

A further object of the invention is to provide such a wheel driveapparatus arranged to provide self-braking.

Still another object of the invention is to provide such a wheel driveapparatus including a drive means, a pair of clutches each having aninput portion and an output portion, gear means connected to the drivemeans for concurrently driving the input portions at different speeds,means for selectively arranging the output portions to be driven by theinput portions individually or concurrently, and means connected to theoutput portions to be driven thereby at preselected speeds when theclutches are ar ranged for driving individually either of the outputportions and to be urged against movement by the output portions whenthe clutches are arranged for concurrently driving the output portions.

A yet further object of the invention is to provide such a wheel driveapparatus having a simple economical construction and providingfacilitated maintenance and operation.

Other objects and advantages of the invention will be apparent from thefollowing description, taken in connection with the accompanyingdrawings wherein:

FIGURE 1 is a schematic perspective view of a portion .of a wheeledvehicle provided with wheel drive apparatus embodying the invention;

FIGURE 2 is a front elevation of the wheel drive apparatus;

FIGURE '3 is a vertical section thereof taken substantially along theline 33 of FIGURE 2;

FIGURE 4 is a horizontal section thereof taken substantially along theline 4-4 of FIGURE 2;

FIGURE 5 is a graph illustrating motor torque versus motor speedobtained by varying the pump cam angle;

FIGURE 6 is a graph illustrating vehicle speed versus draw bar pullobtained with a drive embodying the pres- ,ent invention; and

FIGURE 7 is a similar graph illustrating the conditions obtained bytwo-wheel drive and by four-wheel drive.

In the exemplary embodiment of the invention as shown in the drawings, aplurality of wheel drive apparatuses generally designated 11 areassociated one each with each of the wheels 11 of a suitable vehicle(not shown). Each wheel drive apparatus includes a drive means such asmotor 12. In illustrating the invention, motor 12 is shown to comprise ahydraulic motor of conventional construction, controlledly driven bysuitable conventional hydrostatic drive apparatus generally designated13. As will be obvious to one skilled in the art, however, the drivemeans 12 of apparatus 10 may alternatively comprise an electric motorfor operation by suitable associated electric control means or maycomprise a mechanical input connection as desired.

As shown in FIGURE 1, power means 13 may comprise a suitable driveengine 14 operating a plurality of conventional hydrostatic supply pumps15 and a clutch supply pump 16 through a suitable reduction gear box 17.A conventional oil supply tank and cooler device 18 is associated withthe supply pumps and motors. A suitable selector and control valvedevice 19 is provided. The hydraulic fluid is delivered through valvedevice 19 to all or two of the wheel drive devices 10 through suitableassociated conduits generally designated 21 and conventionaldistribution manifolds 22. The hydrostatic supply pumps mayalternatively comp-rise fixed displacement pumps and variabledisplacement pumps and the motors 12 may alternatively comprise fixeddisplacement motors and variable displacement motors as desired.

Referring now more specifically to FIGURES 2 through 4, wheel driveapparatus '10 may be seen to comprise a tripartite housing 23 having aforward portion 24, a mid-portion 25, and a rear portion 26. Preferably,a substantial portion of the housing is disposed in a recess provided bya central annular flange on wheel 11 extending axially from the wheelhub. As best seen in FIGURE 4, hydraulic motor 12 is carried by theforward portion 24 of the housing and is provided with a drive shaft 27to which is coaxially splined a drive pinion shaft 28 journalled insuitable roller bearings 29 carried by housing portion 25. A drivepinion 30 is formed integral with shaft 28, herein pinion 30illustratively comprises a IS-tooth pinion. An idler gear 31,illustratively having 37 teeth, is journalled on a stub shaft 32 fixedlysecured to housing portion 25 and meshes with pinion 30. Idler gear 31,in turn, meshes with a pair of gears 33 and 34 fixedly secured to a pairof clutch shafts 35 and 36 respectively as shown in FIGURE 3, gear 33having 23 teeth and gear 34 having 46 teeth in the illustratedembodiment. The shafts 35 and 36 are journalled at one end in suitableroller bearings 37 in housing portion 25 and at the opposite end insuitable bearings 38 in housing portion 24. Shafts 35 and 36 are hollowand are arranged to deliver hydraulic fluid to a pair of conventionalwet type double acting clutches 39 and 40 associated respectivelytherewith, the hydraulic fluid being delivered to the interior of thehollow shafts through a suitable connecting fitting 41 at the forwardend of each shaft. As best seen in FIGURE 3, the shafts are sealed tothe connecting fittings by suitable means such as 0- rings 42.

As best seen in FIGURE 3, clutch 39 includes input portions securedagainst rotation relative to shaft 35, and a pair of opposed clutchdrums 44 and 45 freely rotatable on shaft 35 to be selectively driven bythe input portions. Similarly, clutch 40 includes input portions fixedagainst rotation on shaft 36 and a pair of opposed clutch drums 48 and49 freely rotatable thereon. Clutch drum 44 is secured as by welding toa gear 50 illustratively having 17 teeth journalled on shaft 35 bysuitable means such as bushing 51. Clutch drum 45is fixedly secured asby welding to a gear 52, illustratively having 27 teeth, and journalledon shaft 35 by means of a bushing 53. Clutch drum 48 is fixedly securedas by welding to a gear 54, illustratively having 17 teeth, andjournalled on shaft 36 by means of bushing 55. Clutch drum 49 is fixedlysecured to a gear 56 illustratively having 27 teeth and journalled onshaft 36 by a bushing 57. Y

Clutches 39 and 40 are arranged-herein to drive selectively gears 50,52, 54 and 56 by suitable hydraulic operation under control of fluidadmitted through the input shaft to the clutch. Thus, clutch 39 may beoperated selectively to drive drum 44 or drum 45 thereby selectivelydriving gear 50 or gear 52 as desired. Similarly, clutch 40 may beoperated to drive selectively drum 48 or drum 49 to drive selectivelygear 54 or gear 56.

As best seen in FIGURE 3, gears 50 and 54 mesh with a gear 58 formedintegral with a gather shaft 59, gear 58 illustratively herein having 27teeth. One end of gather shaft 59 is journalled on an inner end portion60 of the wheel axle 61 and the other end of gather shaft 59 isjournalled in a suitable bearing 62 carried by housing portion 24.Adjacent bearing 62, gather shaft 59 is provided with a second integralgear 63 meshing with gears 52 and 56, herein gear 63 is provided with 17teeth.

Referring now more specifically to FIGURE 4, gear 63 may be seen to bein meshing engagement with a gear 64, herein illustratively having v51teeth, formed integral with a hollow transfer shaft 65 journalled at oneend in a suitable roller bearing 66 carried by housing portion 24 and atthe other end in a suitable roller bearing 67 carried by housing portion25. A drive pinion shaft 68 is splined to the transfer shaft 65 forcoaxial rotation therewith and is journalled in suitable roller bearings69 and 70 carried by housing portions 25 and 26, respectively. A drivepinion 71 formed integral with shaft 68, herein provided with 8 teeth,meshes with a bull gear 72, herein having 43 teeth, fixed to the wheelaxle 61 comprising the output shaft of the apparatus 10. Wheel axle 61is journalled in suitable roller bearings 73 caI- ried by housingportion 25 and 74 carried by housing portion 26 and provided withsuitable seals 75.

If desired, a hydraulic brake generally designated 76 may be associatedwith the apparatus 10 for braking the wheel 11. As shown in FIGURE 3,the brake 76 may comprise a conventional expandable shoe brake having aninner support 77 secured to housing portion 26 by suitable means such asbolts 78, and a drum portion 79 secured to the wheel 11. In this form ofhydraulic brake, the shoe 80 comprises a hollow annular memberexpandable by means of hydraulic fluid admitted to the interior thereofas through passage 81.

Another feature of wheel drive apparatus 10 is the capability thereof toprovide self-braking by suitable concurrent operation of the clutches 39and 40. Thus, whenever it is desired to brake the wheel 11 by means ofthe clutches, both clutches are concurrently energized thereby providingdifferent ratio gear trains between gathering shaft 59 and gear 31. Suchgear trains can not be concurrently maintained and, thus, one or theother of the clutches slips to compensate for this difference in thegear ratios. The slippage forces cause the wheel 11 to stop, the energythereof being dissipated as heat energy in the clutch. I

Dynamic braking may be obtained by motoring the pump and restricting itsoutput.

Where the apparatus 10 is to be associated with steerable wheels,suitable king pins 82 may be provided on pads 83 carried by housingportion 24. Where the wheels are not steerable, the apparatus may besecured to the vehicle frame by flanges 84 of housing portion 25 whichmay be suitably elongated for this purpose.

As discussed above, the hydrostactic supply pumps 15 may comprise fixeddisplacement pumps. Hydraulic motor 12 may comprise a fixed displacementmotor. Thusly, apparatus 10 may provide a drive of the wheel 11 at fourdifferent preselected speeds depending on which clutch drum is beingdriven. Alternatively, where the pumps 15 comprise variable volumehydraulic pumps, four different speed ranges will be obtained from theapparatus 10 in lieu of the four difierent specific speeds obtainedwhere the pumps are of the fixed displacement type. Still further, wherethe pumps 15 comprise variable volume pumps and the motor 12 comprisevariable volume motors, the pumps and motors may be operated at maximumefficiency at all times notwithstanding a Wide torque and speedrequirement of the drive.

More specifically, where the gear teeth arrangements are as discussedabove, the Wheel drive apparatus 10 provides a gear ratio between shaft28 and axle 61 of 75 to 1 where the gear 54 is selected, a gear ratio of47 to 1 where the gear 50 is selected, a gear ratio of 30 to 1 where thegear 56 is selected, and a gear ratio of 19 to 1 where the gear 52 isselected. Illustratively, with such gear ratios, where the motor 12comprises a 1,250 rpm. motor and the wheel 11 comprises a wheel having anominal tire size of 24.0029, vehicle speeds of 3.5, 5.7, 9.0 and 14.0miles per hour are obtained. However, by simply providing all of thefluid to only two of the wheels 11 rather than to all four, thehydraulic motors of the selected wheels may be operated at 2,500 r.p.m.,thus doubling the above indicated speeds.

In a hydrostatic transmission with a variable volume pump and a fixeddisplacement motor driving through a single speed reduction gearing, thetorque output is proportional to the pressure and speed is proportionalto the flow rate. In such a device, the speed range is controlled bysetting the cam angle of the pump, as illustrated in the graph of FIGURE5 and by varying the speed of the prime mover, but a serious problem isencountered in obtaining a wide speed range because there is only anarrow range in which a hydrostatic system works efliciently, as forexample, approximately in the range of 1,500 to 3,000 rpm. in FIGURE 5.As illustrated the speed range ratio is approximately 2 to 1, and in asystem using a variable volume pump and a variable volume motor, theratio is only about 3 to 1.

In a system embodying the principles of the present invention, thehydrostatic portion of the drive is always operated in the maximumefficiency range, and a wide range of speeds is provided in themechanical gear ratio change mechanism, as illustrated in the graph ofFIGURE 6. This may be accomplished in four steps while maintaining thehydrostatic transmission at maximum efficiency. As seen in FIGURE 6, aspeed range from less than 3 to 7 is provided by using a first gear inthe mechanical assembly while varying the pump cam angle through therange of maximum efficiency, a speed range from 7 to 12.7 is obtained byusing a second gear while varying the pump cam angle, etc. In thismanner, a speed range ratio of approximately 15 to 1 is provided whilemaintaining the hydrostatic transmission within. the high efliciencyrange at any engine speed. Normally, the entire transmission is operatedat maximum speed and minimum torque, and speed is reduced with aconsequent torque increase where needed to accommodate the load.

The control valve device 19 provides for driving either two of the Wheelunits 11 or, alternatively, all of the wheel units. The graph in FIGURE6 illustrates the range of operation in the case of two wheel drive,providing a relatively high speed range and a low torque range ascompared to the conditions illustrated in the graph of FIGURE 7 whereall four wheels are driven, providing a relatively reduced speed rangeand an increased torque range.

The control valve device 19 provides for remote control of the gearratio change clutches controlling the constantly meshed gears in eachwheel assembly to selectively energize the desired clutch correspondingto a desired gear ratio and additionally provides for simultaneouscontrol of two or more wheels to simultaneously vary the speed in eachcontrolled wheel assembly while the vehicle is in motion under loadwithout the need for stopping or synchronizing before shifting gears.

Another important feature of the present apparatus resides in theprovision of a self-contained power Wheel assembly including a wheelwith a drive axle, gearing on the axle for driving it, gear ratio changemechanism supported on the axle, a hydraulic motor driving the gearmechanism and a housing mountable selectively at one or more positionson a single vehicle chassis or frame, dismountable and usable with othervehicles, all constructed around the centrally disposed wheel axle andadapted to be supplied by fluid under pressure from an engine drivenpump integral with the vehicle or pump means associated with some othervehicle detachably connectable with the vehicle utilizing the wheelassembly.

While we have shown and described one embodiment of our invention, it isto be understood that it is capable of many modifications. Changes,therefore, in the construction and arrangement may be made withoutdeparting from the spirit and scope of the invention as defined in theappended claims.

We claim:

1. For use in a vehicle, a self-contained wheel and drive assemblycomprising: a housing including means [for fixed attachment of thehousing to a vehicle; a motor carried by the housing for operation froma power source; a change speed gear transmission carried by the housing,said transmission having an input portion driven by said motor and anoutput portion; and means on said output portion for carrying a wheelfor movably supporting the vehicle, said transmission comprising a pairof shafts concurrently driven by said motor at mutually differentspeeds, and a pair of clutches, one clutch having a first input drivenby one of said shafts and an output selectively driveable by said input,and the other clutch having a second input driven by the other of saidshafts and an output selectively dn'veable by said second input, saidoutputs driving said output portion of the transmission at preselectedspeeds when one of said clutches only is arranged for driving its outputand to be urged against movement by said clutches when said clutches arearranged for concurrently driving said outputs.

2. For use in a vehicle, a self-contained wheel and drive assemblycomprising: a housing; means for mounting the housing on a vehicle; amotor carried by the housing for operation from a power source; a changespeed gear transmission carried by the housing, said transmission havingan input portion driven by said motor and an output drive shaftjournalled Within said housing and having a free end projectingoutwardly of said housing; a wheel including an annular hub; and meansfor supporting said wheel hub solely on said free end of said outputdrive shaft for movably supporting the vehicle, said output shaftfurther including a portion journalling a portion of said change speedgear transmission therein.

3. The self-contained Wheel and drive assembly of claim 2 wherein saidlast-named means rigidly mounts said hub on said shaft.

4. The self-contained wheel and drive assembly of claim 2 wherein saiddrive shaft has an outer end at one end of said housing, and said wheelsupporting means mounts said hub on said outer end to extend axiallyback from said outer end and annularly around said one end of thehousing.

5. The self-contained wheel and drive assembly of claim 2 wherein saiddrive shaft has an outer end at one end of said :housing, and said wheelsupporting means mounts said hub on said outer end to extend axiallyback from said outer end and annularly around said one end of thehousing, over one-half the length of the housing in the direction of theaxis of said drive shaft being disposed radially inwardly of said hub.

6. The self-contained wheel and drive assembly of claim 2 wherein saidtransmission includes clutch means and means for selectively operatingthe clutch means to transmit power to said drive shaft from said motorand to brake rotation of the drive shaft.

7. The self-contained Wheel and drive assembly of claim 2 wherein saiddrive shaft has an outer end at one end of said housing, said wheelsupporting means mounting said hub on said outer end to extend axiallyback from said outer end and annularly around said one end of thehousing, and further including an annular brake disposed coaxially ofsaid drive shaft between said housing end and said hub.

8. The self-contained wheel and drive assembly of claim 7 wherein saidwheel supporting means includes annular wall means extending radiallyoutwardly from said drive shaft to said hub precluding access to saidbrake from axially outwardly thereof.

9. The self-contained wheel and drive assembly of claim 7 wherein saidwheel supporting means includes annular wall means extending radiallyoutwardly from said drive shaft to said hub precluding access to saidbrake from axially outwardly thereof, said brake including a portioncarried by said Wall means for rotation therewith.

References Cited UNITED STATES PATENTS 1,642,106 9/1927 Daubenmeyer18066 1,924,363 8/ 1933 Kanai 18031 2,039,513 5/1936 Baker 180 3,115,20412/1963 Dence --10 FOREIGN PATENTS 426,063 3/1935 Great Britain. 540,2733/ 1956- Italy.

LEO FRIAGLIA, Primary Examiner.

MILTON L. SMITH, BENJAMIN HERSH, Examiners.

2. FOR USE IN A VEHICLE, A SELF-CONTAINED WHEEL AND DRIVE ASSEMBLYCOMPRISING: A HOUSING: MEANS FOR MOUNTING THE HOUSING ON A VEHICLE; AMOTOR CARRIED BY THE HOUSING FOR OPERATION FROM A POWER SOURCE; A CHANGESPEED GEAR TRANSMISSION CARRIED BY THE HOUSING, SAID TRANSMISSION HAVINGAN INPUT PORTION DRIVEN BY SAID MOTOR AND AN OUTPUT DRIVE SHAFTJOURNALLED WITHIN SAID HOUSING AND HAVING A FREE END PROJECTINGOUTWARDLY OF SAID HOUSING; A WHEEL